Officers can claim back tax on their Federations subs and also the flat rate expense allowance. This covered a number of previous allowances (boot allowance) that HMRC rationalised into one.
This should then result in a new tax code.
New tax year ie. 6th April 2018 which will be month 1 payslip should be 1224L.
Personal tax allowance £11,850
Professional subs £259 (membership of Police Federation)
Flat rate expenses £140
Please note tax codes may appear differently to the above due to personal circumstances.